Semiconductor devices are commonly utilized as switches or rectifiers in high-power electric circuits. As one example, power inverters are used in electric and hybrid electric vehicles to provide three phase operating power to the electric drive motor of the vehicle. These semiconductor devices may generate excess heat during operation. For example, the power demands of electric traction motors may fluctuate over a wide range. These fluctuations in power demand can cause temperature changes in the semiconductor devices connected to the traction motors, which may result in degradation from the heat itself or from variations in the coefficients of expansion between the constituent materials.
For this reason, the power modules that house such semiconductor devices are often provided with some form of cooling system. Conventional cooling systems commonly employ a cold plate (e.g., a heat sink) to transfer heat away from the semiconductor device. The heat sink may include a metal body (e.g., aluminum, copper, etc.) having a flat surface and any number of projections (“pin-fins”) extending away from semiconductor device. The flat surface of the heat sink is placed in thermal contact with the semiconductor device (e.g., soldered to a substrate supporting the semiconductor device), and the pin-fins are exposed to a cooling source, typically air or a coolant fluid (e.g., glycol water). Some cooling systems include a pump to circulate coolant fluid through the module. During operation, heat is conducted away from the semiconductor device and into the pin-fins, which are convectively cooled by the cooling medium.
Conventional cooling systems may not adequately cool the power semiconductor devices in all situations. Particularly, conventional cooling systems may be unable to properly direct coolant to certain areas, including those areas that may be in greatest need of additional cooling. This can be a result of the inability to direct fresh coolant to the various portions of the semiconductor devices or the presence of intervening layers such as interconnects and insulating layers. Additionally, many conventional cooling systems can be difficult to manufacture, overly-complicated, and expensive.
Accordingly, it is desirable to provide power modules with semiconductor devices and cooling systems that enable satisfactory cooling. In addition, it is desirable to providing cooling systems with coolant diverters that direct coolant to the most appropriate locations and that are relatively easy and inexpensive to manufacture. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.